The present invention relates to a chair incorporating an adjustable lumbar device, and more particularly relates to a chair having a back, a back covering and an adjustable lumbar device positioned therebetween.
Recently, chair users and seating manufacturers have recognized the value and health benefit to customers of providing good adjustable lumbar support. Many different adjustable lumbar devices and arrangements are known; however, such devices are often expensive, complicated, include numerous parts, and/or have a poor appearance. Further, they are often difficult to adjust and/or not intuitive to adjust, such that customers do not (or are unable to) adjust them.
Aside from the above problems, there is a need for a lumbar device capable of cooperating with a highly flexible back, such as the novel back construction described in U.S. Pat. No. 5,871,258, issued Feb. 16, 1999. For example, where a chair back is highly flexible and also laterally flexible, a laterally stiff lumbar device can undesirably take away from the overall comfort and flexibility of the chair back. Notably, there is a lumbar adjustment device disclosed in the ""258 patent, however it is made from relatively stiff material, such that the chair back tends to conform to a shape of the lumbar device instead of visa versa. Specifically, the lumbar device shown in the ""258 patent is rigid enough to change a shape of the back shell, which may not always result in a best lumbar support arrangement or support. Further, the disclosed lumbar adjustment device includes vertically extending fingers that can get caught in the horizontal slots located in the lumbar area of the back shell during vertical adjustment of the lumbar device, which can limit adjustability or create a poor feel to the operator during adjustment. Still further, this lumbar device includes multiple parts and pieces that must be assembled, and that may come apart or not work properly if abused in the field.
There is also an adjustable lumbar device disclosed in U.S. Pat. No. 6,062,649, issued May 16, 2000. However, like the lumbar device disclosed in the ""258 patent, this adjustable lumbar device is also made of multiple parts and pieces, and has stiff sections. Further, the lumbar device of this patent is made to function with a relatively stiff back and is not made to function with a highly flexible back shell, as in the present invention. Further, it is noted that the lumbar device of this patent teaches the use of guides along edges of the back to guide vertical adjustment of the disclosed lumbar device, which guides can wear and result in warranty.
Accordingly, an adjustable lumbar device is desired that solves the aforementioned problems and that has the aforementioned advantages.
In one aspect of the present invention, a chair includes a back having first edges and a lumbar section with horizontal slots, a back cover covering a front surface of the back and having second edges, and an adjustable lumbar device positioned between the back and back cover. The adjustable lumbar device includes rearwardly-extending detent projections extending into engagement with the horizontal slots for holding the lumbar support in a selected position. The adjustable lumbar support further includes end sections that extend outboard of the second edges and that are configured to be grasp so that a seated user can easily adjust a height of the adjustable lumbar device.
In another aspect of the present invention, a lumbar device includes an elongated polymeric body having front wall sections, rear wall sections, and transverse wall sections. The front wall sections are shaped to provide good lumbar support to a lumbar region of a seated user, and the rear wall sections shaped to slidably engage a front surface of a chair back support. The transverse wall sections join the front and rear wall sections and form vertical ribs in the body. The body, when in a chair-installed position, is flexible and characteristically non-self-supporting so that it is easily bendable about vertical axes that extend parallel the vertical ribs. This makes the body easily bendable to a side-to-side shape of the chair back support. However, the body is at the same time relatively stiff in a direction perpendicular to the front wall sections to provide good ergonomic support to the lumbar region of a seated user""s back.
In another aspect of the present invention, a chair includes a back support, a back covering, and a lumbar device positioned between the back support and the back covering. At least one of the back covering and the lumbar device are translucent or transparent so that a seated user can both see the lumbar device and also see an adjusted position of the lumbar device relative to the back support through one of the back covering and an end of the lumbar device.
In another aspect of the present invention, a method comprises steps of providing a chair having a back support with a front surface, and covering at least a portion of the front surface with a back covering. The method further includes positioning a lumbar device between the front surface of the back support and the portion of the back covering, and vertically adjusting the lumbar device to a selected height and holding the lumbar device in the selected height solely by friction and without use of a vertical guide.
These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.